Adjustable armchair tray

ABSTRACT

A multi-functional adjustable tray that mounts on the arm of a chair to provide a comfortably accessible work surface to support a computer mouse and other IO devices. The adjustable tray may be easily mounted to an arm of a chair and provides width, length, rotation, and storage adjustments. The adjustable tray includes a platform that is pivotally connected to an armchair stop. The armchair stop may be supported by adjustable guides that may be secured to the chair arm by a compression element. The tray may include one or more rotatable joints to allow the platform or IO devices to be tilted to a comfortable working angle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of pendingapplication, entitled ADJUSTABLE ARMCHAIR TRAY, filed by Daniel V.Steenson on Oct. 13, 2005, with application Ser. No. 11/250,654, whichis a continuation-in-part application claiming the priority date fromthe pending utility application entitled ADJUSTABLE ARMCHAIR MOUSE TRAY,filed by Daniel V. Steenson on Aug. 18, 2004 with application Ser. No.10/921,540. Both applications are incorporated herein by thesereferences.

FIELD OF THE INVENTION

The present invention generally relates to the field of computeraccessories. More particularly, the present invention provides anadjustable tray that may be easily mounted to the arm of a chair toprovide a generally planar working surface to support a computer mouseand other accessories, devices and objects.

BACKGROUND OF THE INVENTION

Computers are operated through the use of peripheral systems and devicessuch as a keyboard, roller mouse or optical mouse, pen, joystick,keyboard, keypad, roller ball, trackball, personal digital assistant,cell phone, or similar device or other device, referred to collectivelyas IO devices. IO devices enable a user to interact with a computer ornetwork to send or receive information, make decisions, and carry outvarious other functions. Direct physical contact with, and thereforeclose proximity to, these devices are essential to their operation.

However, in most circumstances a computer user works at a desk and leansforward or sideways from a comfortable sitting position to reach akeyboard or mouse on a desk or other flat surface. Reaching for thekeyboard or the mouse in this way makes it very difficult to maintainproper posture and operate the computer comfortably. Use of IO deviceson a desktop stresses the back, shoulder and the wrist. For wrist stressand carpal tunnel syndrome, numerous products, such as ergonomicallyshaped mice and wrist supports, attempt to address the symptoms of thisstress without addressing the awkward positioning that often causesstrain.

Additionally, persons with debilitating injuries may find that reachingto a desk to use IO devices is difficult or painful. Accordingly, thereis a need for a surface for supporting one or more IO devices thatmaintains a position so that the user may maintain ergonomically correctposture and wrist position.

SUMMARY OF THE INVENTION

The physical stresses resulting from the awkward positioning and use ofIO devices on a desktop may be remedied by mounting an adjustable trayto the left or right arm of a chair in order to facilitate the operationof a mouse or other IO device as a natural extension of a person's armfrom a comfortable seated position. An adjustable tray that can bequickly and efficiently mounted to the arm of a chair may facilitatecomfortable use of a computer keyboard on a person's lap withoutreaching for other IO devices, or use of a keyboard on the platform,further correcting the hunched forward position of many computer users.Multiple trays may be used simultaneously; for example, with a keyboardand a mouse, or split keyboards adapted for use with the left and righthands.

As used herein, the adjustable armchair tray is referred to simply as anadjustable tray. The adjustable tray includes a platform that provides agenerally planar working surface particularly suited for operation of IOdevices. The platform is rotatably fastened to a chair arm attachmentbody, which is adjustable to fit various styles, widths, and lengths ofchair arms.

The platform also preferably includes retainers around its perimeter toprevent devices from sliding off the platform, and retainers to retain apad on the platform when the platform is rotated and stored to the sideof the chair.

The main components of the chair arm attachment body are an armchairstop, guides and one or more compression elements. The armchair stopsupports the platform for use and storage, and connects the platform tothe guides that mount on the arm of a chair. The armchair stoppreferably defines a groove, cavity or interconnecting groove by whichthe armchair stop is pivotally connected by a fastener to the platformthrough one of the slots in the platform. This interconnection allowsthe platform to slide and rotate within the horizontal plane for use,and within the vertical plane for storage of the platform to the side ofa chair.

The adjustable tray includes guides for allowing the adjustable tray tobe mounted to the chair arm. The manner of attachment presents variousembodiments of the adjustable tray. In some embodiments, the guides areslidably interconnected to the armchair stop and fixed against the chairarm by at least one securing device. The securing device is preferably astrap with a buckle for easy attachment. In other embodiments, theguides retract into corresponding cavities in the chair arm.

The adjustable tray is preferably adjustable to various sizes of chairarms. The adjustable tray may also include a pad disposed on theplatform and retained by a retainer around the periphery of the platformor, one or more discrete pad retainers. Cushioning material may be usedon the armchair stop, the plurality of guides, the plurality of verticalguides and the bottom support member to prevent movement of theadjustable tray or marring of the chair during use.

In other embodiments, the armchair stop is securely attached directly tothe chair arm, eliminating the adjustable guides while still allowingthe platform to be placed in a generally horizontal plane for use and agenerally vertical plane for storage. In still other embodiments, arotatable joint may be used to tilt or angle the platform to accommodatethe user's wrist rotation, which is particularly useful for ergonomicuse of keyboards.

The purpose of the foregoing Abstract is to enable the United StatesPatent and Trademark Office and the public generally, and especially thescientists, engineers, and practitioners in the art who are not familiarwith patent or legal terms or phraseology, to determine quickly from acursory inspection, the nature and essence of the technical disclosureof the application. The Abstract is neither intended to define theinvention, which is measured by the claims, nor is it intended to belimiting as to the scope of the invention in any way.

Still other features and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description wherein only the preferred embodiments of theinvention will be described and shown, simply by way of illustration ofthe best modes contemplated to manifest the invention. As will berealized, the invention is capable of modification in various obviousrespects all without departing from the invention. Accordingly, thedrawings and description of the preferred embodiments are to be regardedas illustrative in nature, and not as restrictive in nature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an embodiment of the invention.

FIG. 2 is a side view of the embodiment of FIG. 1, as mounted on a chairarm.

FIG. 3 is a front view of the embodiment of FIG. 1.

FIG. 4 shows a fastener according to an embodiment of the invention.

FIG. 5 is a perspective view of another embodiment of the invention.

FIG. 6 is a side view of an embodiment of the invention where thearmchair stop is secured directly to the chair arm.

FIG. 7 is a side view of an embodiment having a rotatable joint.

FIG. 8 is a side view of an embodiment having a slideable guide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof havebeen shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific forms disclosed; on the contrary, theinvention is to cover all modifications, alternative constructions, andequivalents falling within the spirit and scope of the invention asdefined in the claims.

Embodiments of the present invention include an adjustable tray that maybe mounted on various types of chair arms. Although many different usesare available for the present invention as there are uses for chairs,the present invention will commonly be referenced as an adjustable tray.FIG. 1 shows a top view of an embodiment of the adjustable tray 10. Theadjustable tray 10 includes a platform 12, which provides a generallyplanar surface for IO devices and other writing utensils. Additionally,the platform 12 may be used to write notes, secure a remote control,hold food or a beverage, or facilitate other similar uses. Theadjustable tray 10 may be used on any device or location that isequipped with a chair arm or substantially equivalent structure. Forexample, many automobile seats are now equipped with armrests that theadjustable tray 10 would easily adapt to fit for the previouslymentioned uses.

The shape defined by the perimeter 12 may vary with the application,including square, rectangular, circular, or other shapes. The chairs towhich the adjustable tray 10 may be attached are often mounted onrollers. In normal operation, the user may roll the chair and cause theplatform 12 to contact a desk or other external object. To avoid beingcaptured between the external object and the chair arm, the perimeter ofthe platform 12 may be shaped generally as an oval or an ellipse in someembodiments, and preferably modified by a peak 15. Peak, in thiscontext, means a region of the perimeter that converges more sharplythan an oval or ellipse. The overall oval shape of the platform 12allows the platform 12 to rotate to either side of the chair arm andslide along the object as the object gently pushes it aside. The peak 15insures that the platform 12 swings to one side or the other, ratherthan being captured along the long axis of the chair arm. The perimeterof the platform 12 need not be perfectly elliptical; rather, theperimeter of the platform 12 preferably curves smoothly along the sides,and curving more sharply on the end.

The platform 12 and other parts of the adjustable tray 10 may be builtor molded of any material that allows for strength and ease of use suchas wood, plastic or other similar materials. The platform 12 mayincorporate at least one retainer 14, preferably located around theperiphery of the platform 12, to allow a mouse pad, or other devices tobe retained within the perimeter of the platform 12. The retainer 14provides a boundary that prevents IO devices or other materials fromfalling off the platform 12. In some embodiments, one or more discreteretainers 14 may be placed on all sides of the platform 12 to assurethat a device does not fall off any side of the platform.

A pad 16 or other similar material may be positioned on top of theplatform 12 and configured to be easily replaced when worn out. The pad16 is preferably made of materials similar to those used for basicstand-alone computer mouse pads, typically neoprene. Additionally, thepad 16 may be rubber, plastic or other material that facilitates theoperation of a roller ball mouse, optical mouse or other similarcomputer-interfacing device. To prevent the pad 16 from falling when theplatform 12 is placed in a stored or disengaged position, pad 16 may beheld in place by glue or restraining tabs (not shown) protruding fromthe retainer 14. In other embodiments, the pad retainers may be a moldedpart of the platform or clamps, tie downs, hook and loop fasteners,snaps or other elements that could similarly maintain the correctpositioning of the pad 16 on the platform 12.

In some embodiments of the present invention, IO devices may be rigidlyattached to the platform 12, eliminating the need for retainer 14.Alternatively, the platform 12 may be integrated with the case of the IOdevice, so that the platform 12 and the IO device are presented to theuser as a unit.

A movable fastener 18 passes through a hole 20 in the platform 12,pivotally securing the platform 12 to an armchair stop 22. As hereindefined, the movable fastener 18 is a threaded nut and bolt, a pinconnection with a threaded end for tightening purposes, or any otherelement that provides a rotational pivot for the angular adjustment ofthe platform 12, while still interconnecting the platform 12 with thearmchair stop 22. In the embodiment of movable fastener 18 shown in FIG.4, the movable fastener 18 includes a threaded bolt 40. Threaded nut 42screws onto the shank of bolt 40, capturing the platform 12 betweenthreaded nut 42 and the head 44 of bolt 40. Tightening the nut 42secures the platform 12 and prevents it from rotating; loosening nut 42slightly releases the platform 12 enough to allow rotation to acomfortable position. [check whether should talk about neopreneretainer, 51, 52]

The movable fastener 18 is preferably ergonomically designed or coveredso that it does not interfere with the user during use of devices on theadjustable tray 10. This may be accomplished by incorporating a roundedor other shape that allows it to be easily tightened whilesimultaneously maintaining user comfort. Rounded, in this context, meansthat the nut has no sharp edges exposed to the user when installed.

Referring now to FIG. 2, a side view of the embodiment of FIG. 1, thearmchair stop 22 is shaped to be positioned directly against a chair arm24 while preventing the platform 12 from sliding toward the back of thechair. On some chairs, that position will be where the armresttransitions from horizontal to vertical. The adjustable tray 10 willalso work on different styles of arms and chairs with the only generalcompatibility requirement being that the chair has an armrestequivalent. The armchair stop 22 has a curved or slanted region 26 toaccommodate any curvature of chair arm 24. When the region 26 ofarmchair stop 22 abuts the chair arm 24, the chair arm 24 providesadditional support to the adjustable tray 10.

In a preferred embodiment, the platform 12 is constructed on two levels:a first level that supports an IO device, and a second level lower thanthe first level through which the fastener 18 passes. This two-tierstructure allows the first level to be generally level with the chairarm, so that the user's wrist is approximately straight when using theinput device without interference by the fastener 22. Optionally, awrist pad or cover (not shown) may be placed on the second level to helpsupport the user's wrist.

FIG. 3 is a front view of the embodiment shown in FIG. 1. Referring toFIGS. 1, 2, and 3, the movable fastener 18 flexibly secures the platform12 to armchair stop 22 by passing through the hole 20 in the platform12, through a slot 28 in the armchair stop 22, and into a cavity 30(FIG. 3) in armchair stop 22. The slot 28 in the armchair stop 22 has agenerally horizontal top leg 32 (FIG. 1) having curved regions on eachend and connecting to two generally vertical legs 34 on either side ofarmchair stop 22 (FIG. 2). The slot 28 has additional generallyhorizontal side legs 36 on either side of armchair stop 22, terminatingin an enlarged hole 38. The shape of slot 28 allows the platform 12 tobe positioned on the top of armchair stop 22 for use, or positioned toeither side of chair arm 24 by sliding the fastener 18 from horizontalleg 32 into one of vertical legs 34. Vertical legs 34 need not beprecisely vertical: they may slope fore and aft or side-to-side toaccommodate chair arms of various shapes. Similarly, horizontal sidelegs 36 need not be precisely horizontal.

As a result, a person may use the adjustable tray 10 with the platformhorizontal and then rotate the platform and the movable fastener 18within the slot 28 so that the platform 12 is in a vertical storageposition. The transition is easily made by loosening the movablefastener 18 slightly, and then sliding the movable fastener 18 and theconnected platform 12 within the slot 28 from the horizontal plane tothe vertical plane. In another embodiment, the slot 28 has only onevertical leg 34 so that the platform 12 may be stored only on one sideof the chair arm 24.

Referring to FIG. 2, the platform 12 may be removed from the armchairstop 22 by sliding the movable fastener 18 along the leg 36 of the slot28 to enlarged hole 38. Hole 38 is sufficiently large to allow an end ofmovable fastener 18 to pass through, releasing the movable fastener 18and the platform 12 from the armchair stop 22.

The embodiment of the movable fastener 18 shown in FIG. 4 has a threadedbolt 40 and an ergonomically shaped threaded nut 42. Bolt 40 has a head44 that is small enough to pass through enlarged hole 38, yet stillengage legs 32, 34, and 36 of slot 28. An embodiment of bolt 40 has afrustoconical ring 46 circumvolving the shank of bolt 40 and one or morebosses 48 protruding from the shank of bolt 40.

The hole 20 in the platform 12 may be sized to allow the bolt 40 withthe ring 46 to pass through as a press fit. After the ring 46 passesthrough the hole 20 (FIG. 2), the bolt 40 is captured on the topside ofthe platform 12 by the ring 46 and on the bottom side by head 44, whilestill allowed to move a short distance in an axial direction. The hole20 may optionally be made of a smaller diameter at the upper end, toallow the ring 46 to easily pass through during assembly, while stillcapturing the bolt 40 during operation. In another embodiment, annularring may be replaced with one or more barbs.

One or more bosses 48 engage corresponding axial grooves or similarfeatures in the hole 20 to prevent rotation of the bolt 40 relative tothe platform 12 when the nut 42 is tightened, eliminating the need for awasher and facilitating tightening of the nut 42 to secure the platform12. While the bosses 48 are depicted as cylinders, the bosses 48 may beof any shape that engages the grooves and prevents rotation, including apolyhedron or hemisphere.

The adjustable tray 10 further includes one or more guides 50 connectedto the armchair stop 22. Viewed from above as shown in FIG. 1, theguides 50 are approximately L-shaped on each end, and one leg of eachguide is inserted into a hole 58 and a hole 60 in the armchair stop 22.Holes 58 and 60 are offset, permitting the legs inserted into the slotto be relatively long, accommodating both wide chair arms and narrowchair arms, where the legs overlap each other in the slots. In anembodiment shown in FIG. 5, the rear of the armchair stop 22 may includeone or more recesses 62 sized to accommodate guides 50, allowing guides50 to be adjusted to accommodate a chair arm 24 narrower than armchairstop 22.

In a preferred embodiment depicted in FIG. 5, the guides 50 arecompressed against the sides of the chair arm by at least one securingdevice 52. The securing device 52 as herein defined includes, but is notlimited to, a clamp, tape, bungee cords, string, tie cords, or straps.Each securing device 52 preferable passes around the chair arm 24 andguides 50 and is preferably fastened by a fastener 54. Fastener 54 maybe a Velcro fastener, a Tabler buckle, a clip, or similar bucklingdevice. The compression force of the devices 52 presses the guides 50against the chair arm and into the armchair stop, effectively securingthe adjustable tray 10. This embodiment provides the advantage ofsimplicity and allows the adjustable tray 10 to be quickly and easilymounted to the chair arm with ease.

Another embodiment may include at least one strap slot or loop in eachguide 50 in which to thread the securing devices 52 to compress andsecure the guides 50 to the chair arm. The strap slots preferably run asubstantial length of the guides 50 allowing the securing devices 52 tobe slid or moved to accommodate the configuration of the chair arm andparticularly the support members.

In a preferred embodiment, the guides 50 each have a tab 56 on the endfurthest from the armchair stop 22 to prevent securing devices 52 fromslipping off the ends of guides 50. Guides 50 may also be tapered tobetter conform to curved chair arms.

Referring to FIG. 3, the guides 50 may curve downward in the region 64nearest the armchair stop 22 so that the platform 12 is approximatelylevel with the uppermost surface of guides 50. Without the curved region64, the platform 12 would be positioned above the chair arm 24, causingthe user's wrist to flex upward when using a mouse or other IO device,potentially causing carpal tunnel stress within the wrist. In anotherembodiment, a shallower or deeper curve positions the platform 12 aboveor below the chair arm 24, respectively, which may be comfortable forsome users. Curved region 64 need not be smoothly curved in the S-shapeshown; it may descend sharply in a Z-shape or with perpendicular angles.

Adjustable tray 10 may include multiple sets of guides 50, each settapered, curved, and including features that best fit a class of chairarms. The user may then select the set of guides that best fits theuser's chair.

In another embodiment, shown in FIG. 8, each guide 50 may be insertedinto a corresponding cavity 65 in chair arm 24. The walls of the cavitysupport the guide 50, which in turn supports the armchair stop 22. Eachguide 50 may slide in and out of the cavity, allowing the user to placethe platform 12 a comfortable distance away from the chair arm 24. Insome embodiments, the chair arm 24 has an additional cavity 67 adaptedto accept the armchair stop 22, so that the armchair stop 22 may beretracted into the chair arm 24 and out of the way of the user. In someembodiments, only one guide 50 is required, because there is no need toadapt the adjustable tray 10 to fit the width of the chair arm 24.

Guides 50 may be eliminated by securing armchair stop 22 directly tochair arm 24, as shown in FIG. 6. Armchair stop 22 may be secured withone or more permanent fasteners 68, such as screws or glue, or removablefasteners, such as key and slot hangers. Using a key and slot hanger,one or more keys attached to armchair stop 22 engage slots in chair arm24. Each slot has an enlarged region so that the key may be disengagedfrom the slot, allowing removal of the armchair tray. It is preferableto install the slots on chair arm 24, rather than the key, so that thekey does not protrude from chair arm 24 when armchair stop 22 isremoved.

The armchair stop 22, the guides 50, and the securing devices 52 arepreferably lined with a cushioning material 66. The cushioning material66 allows the guides 50 and the armchair stop 22 to be tightened againstthe surface of a chair without scratching or other marring of the chair.Cushioning material 66 also provides a non-slip surface that preventsmovement during the use of the adjustable tray 10. Cushioning material66 may be any material such as rubber, plastic or cloth that preventsslippage and marring of the arm of the chair. In a preferred embodiment,the cushioning material 66 is neoprene or other non-skid rubberizedmaterial used to form traditional stand-alone mouse pads.

FIG. 7 shows an embodiment of the invention having rotatable joints thatallow the platform 12 to be tilted to comfortably accommodate a user'shand and wrist position while using a keyboard or other IO device. Inparticular, a keyboard that is split into two parts, one for the lefthand and one for the right hand, allows each keyboard segment to berotated to fit the user's hand when the user's arm is resting on thechair arm or held comfortably above it. The left keyboard segment ispreferably tilted or rotated counter-clockwise from the user'sperspective; the right keyboard segment is preferably tilted or rotatedclockwise. The angle of rotation varies with the user, the layout of thechair arm, and the size and configuration of the keyboard. Referring toFIG. 7, the platform 12 is attached to an arm 70 that is divided intothree segments by a first rotatable joint 72 and a second rotatablejoint 74. An inboard segment 76 of the arm 70 is attached to thearmchair stop 22 by the movable fastener 18, and an outboard segment 78of the arm 70 is attached to the platform 12. A middle segment 80connects rotatable joints 72 and 74. In a preferred embodiment, theoutboard segment 78 rotates on a first pin 82, and the middle segment 80rotates about a second pin 84. FIG. 7 shows the outboard segment 78 inan exemplary first position where the user's wrist extends upward,designated as 78, and an exemplary second position where the user'swrist flexes downward, designated as 78′. The rotation of segment 78about joint 74 is not limited to the positions shown and may extend towider or narrower angles.

The outboard segment 78 may be prevented from rotating beyond thedesired angle by static frictional contact between the middle segment 80and the outboard segment 78. The static friction may be overcome byapplying a manual moment to the outboard segment of the arm 70. The easeof rotation may be controlled by using a bolt, machine screw, or lagscrew with a knurled head as the pin 82 so that the bolt may betightened or loosened to control the friction between the segments. Anoptional rotational control device 86 may be used to control rotation,such as a rubber washer, fiber washer, toothed surfaces on segments 78and 80, or other suitable rotation controlling device. Rotation of joint74 may be controlled in a similar manner, including use of a rotationcontrol device 86 between the surfaces of middle segment 80 and inboardsegment 76.

The embodiment shown in FIG. 7 allows the platform to be rotated aboutthe long axis of the arm 70 via rotatable joint 72. In otherembodiments, the arm 70 or the joint 72 may be angled from the long axisof the arm 70 to allow the platform to rotate about an arbitrary axis.Alternatively, the rotatable joint 70 may be combined with a universaljoint to increase flexibility when positioning the platform 12. It mayalso be recognized that some applications require only one rotatablejoint, so that platform 12 has only one axis of rotation.

In some embodiments, the platform 12 is connected to the arm 70 by anadjustable fastener 88. The adjustable fastener 88 may be a bolt with aknurled head, a pin connection with a threaded end for tighteningpurposes, or any other element that provides a rotational pivot forrotational adjustment of the platform 12. A friction element 90 may beplaced between the arm 70 and the platform 12 to prevent rotation of theplatform 12 when the adjustable fastener 88 is tightened. The frictionelement 90 may be a rubber washer, fiber washer, star washer, or otherfrictional device capable of resisting the rotation of platform 12.Alternatively, the arm 70 may be permanently affixed to the platform 12.

While the rotatable joint 72 is particularly useful with keyboardapplications, it is not limited to keyboard applications and may beused, by way of example, with other IO devices such as trackballs. Inembodiments employing rotatable joint 72, it is preferable to insurethat the size of the retainer 14 is adequate to retain the IO devicewhen the platform 12 is tilted away from a level position. As shown inFIG. 7, the retainer 14 is sized to accommodate a keyboard 100.

FIG. 7 also shows an alternative embodiment for controlling the rotationof fastener 18. Flexible material 92 may be affixed to the inboardsegment 76. The fastener 18 passes through the flexible material 92 sothat the frictional contact with the material prevents easy rotation ofthe fastener 18. Flexible material 92 may also cushion the inboard arm76 where it contacts the armchair stop 22 and may prevent rotation ofthe inboard arm 76 relative to the chair arm. Flexible material 92 maybe neoprene, rubber, or similar material capable of lightly gripping theshank of fastener 18, frictionally preventing rotation of the inboardarm 76, or cushioning the inboard arm 76. Optionally, a friction element94 may be placed on the shaft of fastener 18 so that it contactsarmchair stop 22 when fastener 18 is tightened, as in FIG. 2. Thefriction element 94 may be a rubber washer, fiber washer, star washer,or other frictional device capable of resisting the rotation of fastener18.

While there is shown and described the present preferred embodiments ofthe invention, it is to be distinctly understood that this invention isnot limited thereto but may be variously embodied to practice within thescope of the following claims. From the foregoing description, it willbe apparent that various changes may be made without departing from thespirit and scope of the invention as defined by the following claims.

1. An adjustable tray for use on a chair arm having a top surface and awidth dimension, comprising: an armchair stop fastened to the chair arm;a platform defining a securing hole; and a movable fastener having bodyand a head, the body passing through the securing hole into the armchairstop, wherein the platform is rotatably connected to the armchair stopby the movable fastener, and wherein the platform is movable from anapproximately horizontal plane to an approximately vertical plane. 2.The adjustable tray of claim 1, wherein the armchair stop furthercomprises: a generally horizontal surface defining a first slot, thefirst slot adapted to retain the head of the movable fastener and toallow the body of the movable fastener to pass therethrough; and agenerally vertical surface defining a second slot, the second slotconnected to the first slot and adapted to retain the head of themovable fastener and to allow the body of the movable fastener to passtherethrough; wherein the movable fastener passes from the first slot tothe second slot and vice-versa, allowing the platform to be positionedin an approximately horizontal plane and an approximately verticalplane.
 3. The adjustable tray of claim 2, wherein the vertical surfacefurther defines: a third slot in the vertical surface, the third slotconnected to the second slot and adapted to allow the body of themovable fastener to pass therethrough and adapted to retain the head ofthe movable fastener; and a hole connected to the third slot and adaptedto allow the head of the movable fastener to pass therethrough; wherebythe platform may be released from the armchair stop by passing themovable fastener through the third slot and passing the head through theenlarged region.
 4. The adjustable tray of claim 1, further comprising:an elongated guide adjustably connected to the armchair stop, whereinthe elongated guide supports the armchair stop, the elongated guide isadjustable to fit the adjustable tray to the width dimension of thechair arm, and the elongated guide has a first end and a second end; anda compression element circumvolving the chair arm and the elongatedguide to secure the elongated guide to the chair arm.
 5. The adjustabletray of claim 4, wherein the armchair stop further defines a holeadapted to receive the first end of the elongated guide, and wherein thefirst end of the elongated guide is slideable within the hole to adjustthe adjustable tray to fit the width dimension of the chair arm.
 6. Theadjustable tray of claim 4, wherein the elongated guide further definesat least one slit; wherein the compression element passes through theslit to secure the elongated guide to the chair arm.
 7. The adjustabletray of claim 4, wherein the elongated guide is shaped in an S-curve tomaintain the generally planar working surface approximately level withthe top of the chair arm.
 8. The adjustable tray of claim 4, wherein theelongated guide further comprises a tab connected to the second end,wherein the tab is adapted to keep the compression element between thefirst end and the second end.
 9. The adjustable tray of claim 4, whereinthe compression element is a strap.
 10. The adjustable tray of claim 9,further comprising a hook and loop style fastener.
 11. The adjustabletray of claim 1, wherein the armchair stop is rigidly affixed to thechair arm.
 12. The adjustable tray of claim 1, further comprising aretainer affixed to the platform to retain objects on the platform. 13.The adjustable tray of claim 1, further comprising a cushioning materialdisposed on the platform, on the elongated guide, and on the armchairstop.
 14. The adjustable tray of claim 1, wherein the platform defines aperimeter shaped generally as an oval.
 15. The adjustable tray of claim14, wherein the perimeter defines a region converging more sharply thanan oval, whereby the converging region tends to urge the platform asidewhen the platform comes in contact with an obstacle.
 16. The adjustabletray of claim 1, wherein the movable fastener body comprises a threadedshank and a threaded nut fastenable on the threaded shank, the threadednut having no sharp edges when fastened to the shank.
 17. The adjustabletray of claim 16, wherein the movable fastener further comprises afriction device that resists rotation of the movable fastener.
 18. Theadjustable tray of claim 1, wherein the platform further comprises agenerally planar working surface that is approximately level with thetop of the chair arm.
 19. The adjustable tray of claim 1, wherein theplatform further comprises: an arm defining the securing hole and havinga first rotatable joint, wherein the rotatable joint allows thegenerally planar surface to be rotated around a first axis.
 20. Theadjustable tray of claim 19, wherein the arm further comprises: a secondrotatable joint, wherein the second rotatable joint allows the generallyplanar surface to be rotated around a second axis.
 21. The adjustabletray of claim 1, wherein the arm further comprises: flexible materialaffixed to the arm and positioned so that the movable fastener passestherethrough; whereby the flexible material resists rotation of themovable fastener and resists rotation of the arm.
 22. The adjustabletray of claim 1, wherein the platform further comprises an IO device.23. The adjustable tray of claim 22, wherein the IO device comprises akeyboard.
 24. The adjustable tray of claim 1, further comprising: anelongated guide connected to the armchair stop, wherein the elongatedguide supports the armchair stop; wherein the chair arm defines a firstcavity adapted to movably accept the elongated guide; whereby theposition of the armchair stop relative to the chair arm may be adjustedby moving the elongated guide within the first cavity.
 25. Theadjustable tray of claim 24, wherein the chair arm further defines asecond cavity adapted to receive the armchair stop.
 26. An adjustabletray for use on a chair arm having a top surface and a width dimension,comprising: an armchair stop; a platform; a first arm attached to theplatform; a second arm defining a securing hole; a joint rotatablyconnecting the first arm and the second arm, wherein the platform may berotated by rotating the first arm relative to the second arm; and afastener having a body and a head, the body passing through the securinghole into the armchair stop, wherein the second arm is rotatablyconnected to the armchair stop by the movable fastener.
 27. Theadjustable tray of claim 26, wherein the armchair stop furthercomprises: a generally horizontal surface defining a first slot, thefirst slot adapted to retain the head of the movable fastener and toallow the body of the movable fastener to pass therethrough; and agenerally vertical surface defining a second slot, the second slotconnected to the first slot and adapted to retain the head of themovable fastener and to allow the body of the movable fastener to passtherethrough; wherein the movable fastener passes from the first slot tothe second slot and vice-versa, allowing the platform to be positionedin an approximately horizontal plane and an approximately verticalplane.
 28. The adjustable tray of claim 27, wherein the vertical surfacefurther defines: a third slot in the vertical surface, the third slotconnected to the second slot and adapted to allow the body of themovable fastener to pass therethrough and adapted to retain the head ofthe movable fastener; and a hole connected to the third slot and adaptedto allow the head of the movable fastener to pass therethrough; wherebythe platform may be released from the armchair stop by passing themovable fastener through the third slot and passing the head through theenlarged region.
 29. The adjustable tray of claim 26, furthercomprising: an elongated guide adjustably connected to the armchairstop, wherein the elongated guide supports the armchair stop, theelongated guide is adjustable to fit the adjustable tray to the widthdimension of the chair arm, and the elongated guide has a first end anda second end; and a compression element circumvolving the chair arm andthe elongated guide to secure the elongated guide to the chair arm. 30.The adjustable tray of claim 29, wherein the armchair stop furtherdefines a hole adapted to receive the first end of the elongated guide,and wherein the first end of the elongated guide is slideable within thehole to adjust the adjustable tray to fit the width dimension of thechair arm.
 31. The adjustable tray of claim 29, wherein the elongatedguide further defines at least one slit; wherein the compression elementpasses through the slit to secure the elongated guide to the chair arm.32. The adjustable tray of claim 29, wherein the elongated guide isshaped in an S-curve to maintain the generally planar working surfaceapproximately level with the top of the chair arm.
 33. The adjustabletray of claim 29, wherein the elongated guide further comprises a tabconnected to the second end, wherein the tab is adapted to keep thecompression element between the first end and the second end.
 34. Theadjustable tray of claim 29, wherein the compression element is a strap.35. The adjustable tray of claim 34, further comprising a hook and loopstyle fastener.
 36. The adjustable tray of claim 26, wherein thearmchair stop is rigidly affixed to the chair arm.
 37. The adjustabletray of claim 26, further comprising a retainer affixed to the platformto retain objects on the platform.
 38. The adjustable tray of claim 26,further comprising a cushioning material disposed on the platform, onthe elongated guide, and on the armchair stop.
 39. The armchair tray ofclaim 26, wherein the platform is rotatably attached to the first arm.40. The armchair tray of claim 26, wherein the platform is adapted toaccommodate a mouse.
 41. The adjustable tray of claim 26, wherein theplatform further comprises an IO device.
 42. The adjustable tray ofclaim 41, wherein the IO device comprises a keyboard.
 43. The adjustabletray of claim 26, further comprising: an elongated guide connected tothe armchair stop, wherein the elongated guide supports the armchairstop; and wherein the chair arm defines a first cavity adapted tomovably accept the elongated guide; whereby the position of the armchairstop relative to the chair arm may be adjusted by moving the elongatedguide within the first cavity.
 44. The adjustable tray of claim 43,wherein the chair arm further defines a second cavity adapted to receivethe armchair stop.
 45. An adjustable tray for use on a chair arm,comprising: a rotatable platform having at least one generally planarsurface, wherein the platform defines a perimeter shaped generally as anoval and wherein the perimeter defines a region converging more sharplythan an oval, whereby the converging region tends to urge the platformaside when the platform comes in contact with an obstacle.
 46. Theadjustable tray of claim 45, further comprising: a movable fastenerhaving body and a head; and an armchair stop fastened to the chair arm,the armchair stop comprising: a generally horizontal surface defining afirst slot, the first slot adapted to retain the head of the movablefastener and to allow the body of the movable fastener to passtherethrough; and a generally vertical surface defining a second slot,the second slot connected to the first slot and adapted to retain thehead of the movable fastener and to allow the body of the movablefastener to pass therethrough; wherein the movable fastener passes fromthe first slot to the second slot and vice-versa, allowing the platformto be positioned in an approximately horizontal plane and anapproximately vertical plane.
 47. An adjustable tray for use on a chairarm having a top surface and a width dimension, comprising: a platform;and an elongated guide supporting the platform; wherein the chair armdefines a first cavity adapted to movably accept the elongated guide;and whereby the position of the platform relative to the chair arm maybe adjusted by moving the elongated guide within the first cavity. 48.The adjustable tray of claim 47, further comprising: a movable fastenerhaving body and a head; and an armchair stop attached to the elongatedguide, the armchair stop comprising: a generally horizontal surfacedefining a first slot, the first slot adapted to retain the head of themovable fastener and to allow the body of the movable fastener to passtherethrough; and a generally vertical surface defining a second slot,the second slot connected to the first slot and adapted to retain thehead of the movable fastener and to allow the body of the movablefastener to pass therethrough; wherein the movable fastener passes fromthe first slot to the second slot and vice-versa, allowing the platformto be positioned in an approximately horizontal plane and anapproximately vertical plane.
 49. An adjustable tray, for use on a chairarm having a top and defining a width, comprising: a platformcomprising: a planar working surface having a curved perimeter, theperimeter defining a peak wherein the peak serves to urge the platformaside when the platform contacts an obstacle; and a second surfaceoffset from the plane of the first surface and defining a securing hole;a movable fastener; an armchair stop having an approximately horizontaltop, an approximately vertical first side, and an approximately verticalsecond side; the armchair stop defining an elongated slot in the top,the first side, and the second side, and a cavity, wherein the platformis rotatably connected to the armchair stop by the movable fastener, andwherein the movable fastener passes through the securing hole, throughthe elongated slot, and into the cavity, allowing the movable fastenerto pass along the slot to place the platform in a horizontal plane andin a vertical plane, the armchair stop further defining a first hole inthe first side and a second hole in the second side, offset from thefirst hole; a first guide comprising a first leg insertable in the firsthole and a second leg adapted to conform to the chair arm; a secondguide comprising a third leg insertable in the second hole and a fourthleg adapted to conform to the chair arm; a compression element capableof passing around the first and second guides and the chair arm tosecure the first and second guides to the chair arm, whereby the firstleg and third leg of the first and second guides, respectively, areinsertable into the first and second holes a distance appropriate toaccommodate the width of the chair arm, and holding the armchair stopand platform so that the working surface is approximately level with thetop of the chair arm when the first and second guides are secured to thechair arm.
 50. An adjustable tray, comprising: platform means forsupporting an input/output device; body means for supporting theplatform means in a generally horizontal and generally vertical plane;fastening means for fastening the platform to the body means; andattachment means for attaching the body means to a chair arm.